Apparatus for hauling ore in open pit mines



May 15, 1962 E. N. BROWN APPARATUS FOR HAULING ORE IN OPEN PIT MINESFiled Aug. 31, 1959 5 Sheets-Sheet 1 INVENTOR, ERNEST N. BROWN BY W ,4TTOPN E Y5 mm .QN

May 15, 1962 E. N. BROWN APPARATUS FOR HAULING oRE IN OPEN PIT MINESFiled Aug. 51, 1959 5 Sheets-Sheet 2 INVENTOR, ERNEST /V, BROWN BYATTORNEYS May 15, 1962 E. N. BROWN A APPARATUS FOR HAULING ORE IN OPENPIT MINES Filed Aug. 51, 1959 5 Sheets-Sheet 3 IN VEN TOR,

ERNEST N. BROWN BY ay/vm ATTORNEYS May 15, 1962 E. N. BROWN APPARATUSFOR HAULING ORE IN OPEN PIT MINES 5 Sheets-Sheet 4 Filed Aug. 51, 1959INVENTOR, ERNEST N, B/Pow/v ATTORNEYS May 15, 1962 E. N. BROWN 3,034,669

APPARATUS FOR HAULING ORE IN OPEN PIT MINES Filed Aug. 51, 1959 5Sheets-Sheet 5 f/a 7 INVENTOR, fie. f2, ERNEST N. BROWN ATTOIP/VEYUnited States Patent 3,034,669 APPARATUS FOR HAULING ()RE IN OPEN PliTMINES Ernest N. Brown, Aurora, Colo., assignor to Steams- RogersManufacturing Company, Denver, Colo., a corporation of Colorado FilledAug. 31, 1959, Ser. No. 837,033 17 (llairns. (Cl. Mat-1&4)

This invention relates to haulage systems for open pit mines and, morespecifically, to mine skips together with the methods and apparatus usedto load, haul and unload same.

In the ordinary open pit mining operation, the ore is taken from benchesat Varying levels below the pit rim and loaded into heavy-duty dumptrucks which may have capacities of upwards of forty tons for haulage toloading stations at the foot of inclined trackage laid on the slopingwalls of the pit. At each loading station, the ore or waste material istransferred from the dump truck to Waiting mine skips which are used tohaul it up the inclined tracks to a processing station located on thepit rim or one of the higher benches where it is unloaded automatically.

One of the most significant and serious problems encountered in an openpit mining operation of this type is the damage to the mine skipsbrought about when they are loaded from the dump trucks. It is notuncommon, for example, to handle single chunks of material Weighing manytons and having minimum dimensions several feet in length although theyare usually quite irregular in shape with sharp jagged edges andcorners. Quite obviously, dropping loads such as this from a height ofseveral feet at a loading station into the bottom of a mine ski-p can,and does, cause considerable damage resulting in substantial equipmentrepair, maintenance and replacement costs. There is also the importantproblem of equipment breakdowns in service that cause appreciabledowntime, production losses and increased operating costs.

A number of different attempts have been made in the past to solve thisproblem, most of which involved the use of specially designed andreinforced skip buckets and carriages supposedly adapted to resist thesetremendous loading shocks; however, up to the present time these unitshave met with only slight success and much still remains to be done byway of satisfying the needs of the mining industry in this area. insofaras is known, all of the prior art open pit haulage systems and methodsinclude the step of transferring the newly-mined ore and overburden fromthe body of a truck or other vehicle to carriage-supported skip bucketsmounted on inclined trackways. it has now been found in accordance withthe teaching of the instant invention that the aforementioneddifiiculties can be almost completely overcome by the novel expedient ofusing the same unit as both the truck body and skip bucket thuseliminating the step of transferring material therebetween. Atrunnion-supported truck body is removably mounted upon the bed of anore truck and is loaded on one of the benches with the newly-rnined oreand overburden in the conventional manner. The truck then moves to aloading station at the foot of the inclined trackway where largeoverhead traveling cranes mounted for transverse movement lift the truckbody from the bed and set it down on a waiting skip carriage fortransfer to the unloading station on the rim of the pit or at somehigher bench along the track. The crane is used to lower an empty bodyon the truck for the next run. The loaded truck body, which is nowfunctioning as a skip bucket, is pulled up the inclined trackway whereit is dumped automatically into an ore bin underneath the unloadingstation. This haulassists age method, of course, completely eliminatesthe step of transferring the ore from the truck body to the skip bucketand the attendant damage to the equipment.

It is, therefore, the principal object of the present invent to providea novel and improved haulage system for open pit mines.

A second object of the invention of the class described is the provisionof a method of hauling ore from open pit mines that completelyeliminates the step of transferring ore from the ore truck to the mineskip.

A third object is to provide a specially-designed combination truck bodyand skip bucket for use with open pit mine haulage systems.

Another object of the invention is the provision of an improvedautomatic cam-actuated dumping mechanism for skip buckets.

Still another object is to provide a skip carriage that includesadjustable supports adapted to maintain the bed thereof in substantiallyhorizontal position so that the ore buckets can be carried withoutspillage While traversing trackways of varying inclinations.

An additional objective of the claimed invention is to provide anoverhead traveling crane system for use in transferring the combinationtruck bodies and skip buckets between the chassis of the ore trucks andthe skip carriages.

Further objects of the invention are to provide an orehauling system foropen pit mines which is economical in that it utilizes dual-purpose orecarriers, considerably lessens damage to equipment, reduces down-timefor the repair, maintenance and replacement of damaged units, and lowerslabor costs; a system of the type described that is more versatile thanthe prior art assemblies for this purpose; and, one that is rugged andfully adaptable to many different open pit mining operations.

Other objects will be in part apparent and in part pointed outspecifically hereinafter in connection with the description of thedrawings that follows, and in which:

FIGURE 1 is a side elevation, portions of which have been shown insection and other portions broken away to conserve space, illustratingthe open pit ore-hauling system of the present invention including theloading and unloading stations, the inclined trackway extendingtherebetween, the skip buckets and carriage therefor, the travelingcrane and the ore bin;

FIGURE 2 is side elevation of the combination truck body and skip bucketshowing the near side removed and the bottom in section;

FIGURE 3 is a fragmentary top plan View to an enlarged scale showing therail-mounted skip carriage with the ore bucket mounted thereon and thecable-hoist yoke used to haul the assembly up the trackway;

FIGURE 4 is a fragmentary elevation to an enlarged scale showing theleveling mechanism for the skip carriage;

FIGURE 5 is a fragmentary end elevation showing further details of thescissor assembly in the leveling mechanism of FIGURE 4;

FIGURE 6 is a transverse section to an enlarged scale taken along line6-6 of FIGURE 1 showing the automatic cam-actuated dumping mechanismlocated adjacent the unloading station prior to the withdrawal of thetrunnion supports;

FIGURE 7 is a fragmentary section similar to FIG URE 6 except that thecam has moved the trunnion supports out of the way preparatory toemptying the skip bucket into the ore bin;

FIGURE 8 is a longitudinal section taken along line 8-8 of FIGURE 6;

FIGURE 9 is a side elevation similar to FIGURE 1, but to an enlargedscale, showing a modified form of ore-bucket dumping mechanism wherein adifferent cam design is utilized to retract the trunnion supports and apivotally-mounted arm rather than a scroll is used to raise thetrunnions free of their supports;

FIGURE is a fragmentary section taken along line 1010 of FIGURE 9showing the trunnion supports in extended position prior to withdrawalthereof by the cam;

FIGURE 11 is a section similar to FIGURE 10 except that the cam hasretracted the trunnion supports;

FIGURE 12 is a fragmentary top plan view to an enlarged scale showing afurther modified form of dumping mechanism wherein a different type ofretractable ore bucket support is used and engages a foot on the side ofthe bucket rather than the trunnion; and,

FIGURE 13 is a transverse section taken along line 13-13 of FIGURE 12showing the ore bucket support in extended position in dotted linesalong with the construction by which the cam for actuating the lattercan be rendered inoperative if the ore bucket is to move on up to anunloading station at a higher level before being emptied.

Referring now to the drawings, and in particular to FIGURE 1 thereof, itwill be seen that the ore haulage system for open pit mines of thepresent invention includes a loading station and an unloading station,both of which have been indicated in a general way by numerals 10 and12, respectively. These stations are interconnected with one another byan inclined trackway 14 that is bedded along the sloping walls of theopen pit mine. The loading station 10 is usually located at the lowerend of the track-way on a so-called bench or ledge; however, it isentirely possible that two or more loading stations would be used atvarying levels below the rim of the pit. The unloading station 12, onthe other hand, is customarily located on the rim of the pit andincludes some type of ore bin or hopper 16 of conventional design.

The inclined trackway 14 comprises at least one pair of parallel railsupon which is mounted a skip carriage that has been designated generallyby numeral 18 and which will be described in detail presently.Preferably, two sets of tracks are used arranged in side-by-siderelation, one carrying a loaded skip bucket 20 up to the ore bin whilethe other is returning an empty bucket to the loading station; however,a single-track system is also usable and has been illustrated forpurposes of simplification. The wheeled carriages 18 with the orebuckets 20 supported thereon are hauled up the trackway by means ofsuitable winch mechanisms 22 located at the unloading station. Also,adjacent the unloading station, each pair of rails is provided with anautomatic dumping mechanism indicated generally by numeral 24 and whichis operative to empty the ore or skip buckets into the hopper 16.Several forms of the dumping mechanism 24 have been illustrated and willbe described in detail hereinafter.

The skip buckets 20 comprise one of the most significant contributionsof the present invention as they are also the truck bodies loaded at themine face in addition to being the ore carriers of the inclined haulagesystem. Thus, the method and apparatus required to accomplish thetransfer of these ore buckets 20 from the trucks to the skip carriages,in addition, constitute a novel aspect of the instant invention.

'From an examination of FIGURE 1 it will be seen that the bench 26 atwhich the loading station 10 is located, includes a transverselyextending overhead traveling crane assembly, indicated in a general wayby numeral 28, which comprises a base of foundation 30, a plurality ofuprights 32 supported on the base and interconnected by crossframeelements 34, upright rail supports 36 carrying rails 38 interconnectingthe upper ends thereof, and a traveling crane 40 mounted on the railsfor transverse rolling movement across the loading station. Asillustrated, the traveling crane 40 is of the gantry-type having abridge 42 mounted on the rails, a hoisting unit 44 mounted on the bridgefor rolling movement between the ends thereof, and a yoke 46 suspendedfrom the snatch-blocks 48 of the hoisting unit. This yoke is providedwith legs 50, the lower ends of which are formed to provide upwardlyopening hooks 52 positioned and adapted to receive the trunnions 54depending from the sides 56 of the skip buckets 20.

In the preferred embodiment of the invention, a pair of traveling cranesare used, one to carry the loaded ore buckets from the truck to theawaiting carriage at the loading station and the other to transfer theempty buckets on the second track from the carriage to the truck.Ordinarily, the truck will move into a stall on one side of theunloading station where the loaded body will be lifted from the chassiseither by one of the traveling cranes or some other suitable apparatusfor this purpose. The crane will then move over along side the inclinedtrackway in position to lower the loaded truck body or ore bucket ontothe skip carriage as soon as the empty bucket is removed therefrom. Theother crane is used to lift the empty body from the carriage and carryit to a waiting truck chassis where it is mounted for return to themine. As soon as the empty body is removed from the carriage, thefirst-mentioned crane moves into position and lowers the full bodythereon. In the meantime, the chassis of the truck that was lastseparated from its body will move around to the other side of theloading station and into a stall underneath the second crane from whichit will receive an unloaded body. Of course, the number of sets oftracks, trucks, etc., will depend on the cycling time of these variousoperations for a particular mine which are in turn dependant upon thecapacities of the various units, the distances between the working faceof the mine and loading station, and the length of track that must benegotiated between the loading station and ore bin.

Now, referring to FIGURE 2 for a brief description of the ore bucket 20,it will be seen that it comprises generally a heavy-duty truck bodyhaving spaced sides 56, a bottom 58, a forwardly and upwardly inclinedfront end 60 with a cab shield 62 depending therefrom, and a rearwardlyand upwardly inclined tail gate 64. Conventional truck bodies havingcapacities of upwards of forty tons may be used if modified to includethe trunnions 54 depending from the sides thereof and suitable means fordetachably connecting same to the chassis. Obviously, with the exceptionof the aforementioned modifications, a number of different truck bodystyles and designs could be used with equal success.

The skip carriage 18 can best be seen in FIGURES 3, 4 and 5 to whichreference will now be had. A generally rectangular wheel-supported mainframe 66 is mounted for rolling movement along the rails of the tracksin substantially parallel relation thereto although inclined withrespect to the horizontal. The main frame, however, supports anadjustable frame 68 in position to carry the skip buckets 20 insubstantially horizontal or level relation such that the contentsthereof will not be spilled from the partially open tail end. In thespecific form illustrated, main frame 66 includes inner and outersideframe elements 70 and 72, respectively, arranged in spacedsubstantially parallel relation to one another with the wheels 74journalled for rotation therebetween and at the front and rear endsthereof. Spacers 76 are preferably located at intervals throughout thelength of the side frame elements to maintain a fixed spaced relation.Front and rear transverse elements 78 and 80, respectively, connect theside frame assemblies together and maintain the grooved wheels 74 inproper position to receive the rails. A pair of front trunnion saddles82 depend from the inner side frame elements 70 of the main frame inopposed relation to one another and in position to receive the reartrunnions 54 that are located near the tailgate of the skip bucket ortruck body. These trunnion saddles are fixed although they define atransverse pivot axis for the rear end of the skip bucket as the frontend thereof is raised and lowered with the adjustable frame of the skipcarriage in a manner to be described shortly.

The adjustable frame 68 is generally U-shaped and is positioned withinthe confines of the main frame such that it opens toward the unloadingstation which, for the purposes of the present description, has beendesignated the front end of the skip carriage although the rear end ofthe skip: bucket when referenced to the cab or driving compartment ofthe truck chassis. The spaced legs 34 of the adjustable frame have theirfront ends pivotally attached to pins 86 depending from the innerelements 70' of the main frame while the rear ends thereof areinterconnected by a transverse element 88 positioned above the reartransverse element 8010f the main frame. Thus, the rear end of theadjustable frame 68 is free to swing up and down relative to the mainframe 66 in order to maintain the desired level position of the orebucket 20, the front end of which is supported on trunnions 54 that restwithin rear trunnion saddles 90 carried by the legs of said adjustableframe aft of the pivot axis.

Actual leveling of the ore bucket is accomplished by means of ascrew-actuated scissor-type linkage 2 interconnecting the transverseelements 80 and 88 of the main and adjustable frames. While it isobvious that such adjustment could be accomplished with variousmechanisms, the particular one shown comprises links $4 and 96 havingtheir adjacent ends pi-votally attached for movement about a common axisto the cars 98 of a thrust collar 1% while the remote ends thereof arepivotally connected to the transverse elements 30 and 88, respectively,of the main and adjustable frames. An intermediate transverse frameelement 192 interconnects the inner sideframe elements of the main frameand provides a fixed support for the front end of adjustment screw ll-lll that is mounted for rotation therein. The adjustment screw is providedwith spaced abutments 106 located on opposite sides of the inch of frameelement 102 that are adapted to prevent axial movement of the screwwhile the threaded end 108 thereof turns within the thrust collar in amanner to open or close the scissor linkage thereby raising and loweringthe adjustable frame. In actual practice, the foregoing adjustments tomaintain the skip buckets in a level relation would only be made at rareintervals, once at the time the haulage system is installed andthereafter whenever the system is moved to a new location or the slopeof the pit walls changes materially due to settling and working atdiiferent bench and ore bin levels.

As shown in FIGURE 3, a rope or cable yoke fill is attached to the frontcorners of the main frame of the skip carriage while the central portionof the yoke is attached to the line 112 from the drum of the winch 22.As would be expected, winding line 112 onto the winch drum hauls thecarriage and loaded skip bucket up the inclined track from the loadingstation to the unloading station where the bucket is automaticallyemptied into the ore bin. Of course, reversing this procedure lowers theempty bucket and carriage to the loading station for transfer to thetruck chassis by means of the traveling crane.

Before proceeding with a detailed explanation of the several automaticdumping mechanisms that have been illustrated herein and which functionto empty the skip buckets into the ore bin or hopper at the unloadingstation, it will be well to first examine the fundamental requirementscommon to each of these mechanisms. To begin with, the pairs oftrunnions located near the front and rear ends of the skip buckets caneasily be carrying loads in excess of twenty-five tons including boththe truck body and ore. It is necessary in order to dump the skipbuckets that the supports on the skip carriage that hold up the rear endof the skip bucket, namely, front trunnion saddles 82, be retracted insome manner. Before this can be accomplished, however, these fronttrunnion supports or saddles must first be unloaded; hence, some type ofauxiliary trunnion support having a cam surface adapted to lift thetrunnnions free of the retractable saddles is required and this usuallytakes the form of an arched track section or scroll. Then, once thefront trunnion saddles are unloaded, a cam follower carried therebyoperates within a second cam track of some type to retract the saddlesand permit the skip bucket to dump as it traverses a downwardly curvedportion of the firstmentioned arched track section or scroll. Of course,both of these camming mechanisms must be operative to return the skipbucket and retractable trunnion supports to their former positions afterthe dumping cycle has been completed preparatory to returning the emptyskip bucket to the loading station. In addition to the above, it may bedesirable to render both the dumping scroll and trunnion supportretracting cam inoperative so that the loaded ore buckets can bypass agiven unloading station to be emptied at one located at a higher levelon the inclined haulage-way. As the description proceeds, it will befound that the foregoing requirements are met in each of the automaticdumping systems illustrated herein.

Specifically, with reference to FIGURES 6, 7 and 8, the firset form ofautomatic unloading or dumping mechanism 24 will now be described indetail. At each unloading station, transverse frame elements 114interconnect the beams 116 upon which the rails 14 are mounted. Thesetransverse elements 114 provide a base for the foldable or otherwisedemountable upright scroll supports 11% that carry the dumping scroll120. One dumping scroll 12th is located on each side of the center ofthe track in parallel relation to the rails but in longitudinalalignment with the pair of trunnions 54' located on the rear end of thetruck body. The lead or downhill section 122 of the scroll 129 isupwardly inclined at a greater inclination than the rails starting froma low point beneath the trunnion path. Therefore, as the ore bucketenters the unloading station, the rear pair of trunnions move onto thedownhill section 122 of dumping scroll 12% and are lifted thereby ofi oftheir supports 32 which form a part of the carriage. It is thiscondition which has been illustrated in FIGURE 6.

Now, as the trunnions progress up the lead section of the dumping scrolland are lifted free of their supports, these supports become unloaded sothat they can be moved out of the way. The inner side frame members 7 hof the skip carriage are provided with brackets 124- to which thetrunnion supports 82 are attached for pivotal rocking movement betweenthe extended position of FIG- URE 6 and the retracted position of FIGURE7. Stops 126 are provided on opposed surfaces of the brackets andtrunnion supports positioned and adapted to maintain the latter inextended position While loaded as in FIG- URE 6.

Movement of the trunnion supports between extended and retractedpositions is accomplished by means of a cam track 128 located underneaththe dumping scroll on upright scroll supports 118 and a rocker arm 130carried by the trunnion supports with a cam follower 132; on the freeend thereof that rides in the cam track. The cam track includes anupwardly inclined section 134 (FIGURE 8) of a generally channel-shapedcross section which is operative to lift the rocker arm 13% as the camfollower moves through the channel thereby tilting the trunnion supportfrom itsextended to its retracted position. The inclined section 134 ofthe cam track is positioned substantially underneath the high point ofthe dumping scroll so that it is operative to rock the trunnion supportsfrom underneath the trunnions only when the former have been unloaded.Once the trunnion supports have moved from beneath the trunnions, theuphill or terminal section 136 of the cam track once again assumes aparallel relation to the rails thereby holding the trunnion support inretracted position while the dumping operation is completed.

Now, after the trunnion supports have been retracted, the rear pair oftrunnions that have been supported thereby proceed to roll along theuphill or terminal section 138 of the dumping scroll 120 which curvesdownwardly between the rails. This, of course, lowers the rear end ofthe skip bucket as the front or downhill end thereof pivots about therear set of trunnions cradled in fixed trunnion supports 90 causing theore to be discharged over the tailgate 64 into the ore bin as clearlyshown by dotted lines in FIGURE 1. Note in this connection that the camfollower 132 and the rear trunnions 54 do not leave the cam track anddumping scroll 120 during the unloading operation.

After the load has been discharged into the ore bin, the winch isreversed by the winch operator permitting the ore bucket to return downthe trackway to the loading station. Obviously, as the ore bucketreverses direction the dumping scroll will again lift the rear endthereof and the cam track will move the trunnion supports back intoextended position beneath the rear trunnions for the return trip.

Note, also, that in this particular embodiment of the invention both thedumping scroll 120 and the cam track 128 are carried by the uprightsupport elements 118 which are hingedly attached to the transverse frameelements 114 by means of hinge elements 140. Thus, by folding thedumping scroll and cam track into the dotted line position of FIGURE 6,the dumping mechanism can be rendered completely inoperative allowingthe ore bucket to by-pass the unloading station and proceed to anotherlocated at a higher bench level or on the pit rim. Such a feature wouldbe quite useful, for example, if separate unloading stations and binswere used for overburden and mine run ore.

The second unloading or dumping assembly 24a of the present inventionhas been illustrated in FIGURES 9, l and 11 to which reference will nowbe had. This embodiment of the invention differs from the one justdescribed in two principal aspects, namely, the substitution of a pairof rocker arms 142 for the dumping scroll and the relocation of the camtrack 128a on the outside of the rails 14. Transverse elements 114- atthe unloading station are eliminated and replaced by a transverse shaft144 journalled for rotation within bearings 146 carried by a suitableauxiliary frame structure depending from rail supports 116 and which hasbeen designated in its entirety by numeral 148 as the particular designthereof is of no patentable significance. A fixed stop 150 is attachedto each of the rail supports 116 extending inwardly therefrom inposition to engage rocker arm 142 and retain same in the proper locationto pick up the rear trunnions of the ore bucket. In addition, aretractable stop 152 also depends from each of the rail supports aheador upgrade of the fixed stop and in position to limit the forward travelof the rocker arm. Stop 152 is mounted for telescoping movement within atubular element 154 projecting inwardly from the rail support as clearlyshown in FIGURE 11. When stop 152 is retracted or telescoped within tube154, arm 142 can b lowered to the dot-dash line lowest position ofFIGURE 9 and thus be rendered inoperative so that the ore bucket canby-pass the unloading station without being dumped for the reasons thathave already been described.

With the rocker arms 142 located as shown in full lines in FIGURE 9, theforked upper end thereof 156 is in position to receive the rear pair oftrunnions of the ore bucket as it proceeds up the trackway. Once thearms 142 have picked up the trunnions, they rock forwardly raising therear end of the ore bucket off of the trunnion supports 82a at the frontend of the skip carriage thus freeing them for movement into retractedposition. Suitable cross braces 158 preferably interconnect the rockerarms for simultaneous movement so that the ore bucket will not becomeskewed in relation to the rails.

The trunnion supports 82a are changed very little except that the rockerarms 130a are elongated and extend outwardly therefrom rather thaninwardly as in the FIG- URES 68 embodiment. These trunnion supports 82aare mounted for swinging movement between the extended position ofFIGURE 10 and the retracted position of FIGURE 11 within the slightlymodified trunnion support brackets 12401. The trunnion supports andbracketse therefor still include the stops 126 operative to maintain theextended position of the former when under load. The outside of thetrunnion support brackets 124a is provided with an upwardly ranging slot160 positioned and adapted to receive the rocker arm 130a for up anddown movement.

The cam track 128a is mounted on the outside of the rails in thisembodiment and is supported by an auxiliary frame structure that dependsfrom the rail supports and includes structs 162, main support elements164 and tiltable uprights 166. Uprights 166 are hingedly attached to themain supports by hinge connections 168 that provide for swingingmovement thereof between the full line operative position of FIGURES l0and 11 and the dotted line inoperative position of FIGURE 10. Aretaining pin 170 interconnects one of the uprights 166 with itsassociated hinge connection 168 to maintain the former in operativeposition except when it is desirable to have the ore bucket by-pass theunloading station without being dumped.

The cam tracks 124a are, of course, reversed from those previouslydescribed by reason of their being mounted on the outside rather thanthe inside of the rails. Thus the inclined section 134a thereof (FIGURE9) slopes downwardly and forwardly to accomplish retraction of thetrunnion supports rather than upwardly. Here again, the inclined medialsection 134a of the cam track 128a becomes operative to retract thetrunnion supports only after the rocker arms 142 have raised the tailend of the ore bucket.

Once the trunnion supports have been retracted into the position shownin FIGURE 11, the rocker arms 142 swing forwardly and downwardly to theintermediate dot dash line position of FIGURE 9 where they engage theretractable stop 152 and lower the rear end of the ore body to thedumping position that is also shown by dot dash lines in FIGURE 9. Theore bucket again pivots about the front pair of trunnions cradled intrunnion supports 96 and discharges the contents over the slopingtailgate 64- into the ore bin. As before reversal of the skip carriageplaces the rear pair of trunnions back on the trunnion supports whichhave been returned to extended position by the cam track.

Finally, FIGURES 12 and 13 show the third form of dumping assembly 24bthat differs from the two already described in that it includes afurther modified form of cam track 1281) and associated elements. Thedumping scroll 120 and hinged support 118 therefore are the same as inthe first modification of FIGURES 6-8; however, the cam track 12812 isnot carried thereby but is mounted on the top of a pair of cam tracksupport brackets 172 that depend from the rail supports 116 for swingingmovement between the full-line operative position of FIGURES l2 and 13and the dotted line in operative position of FIGURE 13 by reason of thehinged connection 174 therebetween. As shown, cam track 12812 comprisesan upturned channel adapted to receive cam followers 132b mounted on thefree end of arm 13%. This arm 130b, instead of being attached to thesupport for the ore bucket 82b in fixed relation thereto, is pivotallymounted on a pivot pin 176 so that it can slide in and out axiallythrough a guide member 178 in the bracket 12412 to move support 82bbetween its extended and retracted positions shown in FIGURE 13 by fulland dotted lines. Note that bracket 82b while it has substantially thesame design as bracket 82a of the FIGURES 911 modification, does notsupport the rear pair of trunnions on the ore bucket, but instead, holdsup the bucket by means of brackets 180 that extend outwardly from thesides thereof. Of course, as these trunnions ride up on the dumpingscroll and lift the tail end of the ore bucket, the brackets 82b areunloaded, as before, for

hinged movement into retracted position. Brackets 124i: and supports 82bare likewise operatively interconnected by the stops 126 which cooperatewith one another to maintain said brackets in extended position whenloaded.

In this instance, the medial section 1134b of the cam track is angularlyoffset laterally rather than up or down to accomplish movement of thesupport 82b between its extended and retracted positions as the camfollower 1321) rolls within the cam track and operates arm 13Gb. Onceagain, the dumping mechanism can be rendered inoperative so that the orebucket can move onto a more elevated unloading station by the simpleexpedient of folding down the dumping scroll 120 and swinging the camtrack 12% out of the way.

Having thus described the several useful and novel features of theinstant open pit mine haulage system along with the methods andapparatus used therewith, it will be apparent that the many worthwhileobjectives for which they were designed have been achieved. Although buta few embodiments of the present invention have been illustrated anddescribed in connection with the accompanying drawings, I realize thatmany changes and modifications therein are possible for those skilled inthe art within the broad teaching hereof; hence, it is my intention thatthe scope of protection afforded hereby shall be limited only insofar assaid limitations are expressly set forth in the appended claims.

What is claimed is:

1. In an ore haulage system of the type used in open pit mines and thelike which includes, an inclined trackway laid on the sloping walls ofthe pit, a loading station on the inclined tr-ackway near the workingface of the mine, an unloading station including an ore bin located onthe traokway above the loading station, a wheeled carriage mounted onthe trackway for movement between the loading and unloading stations andhoist means located at the unloading station and operatively connectedto the carriage for moving same up and down the trackway, the improvedore transfer assembly which comprises truck-type vehicles having awheeled chassis movable between the working face and loading station, adetachable open topped ore receptacle providing a combination truck bodyfor use on the truck chassis and an ore bucket for use on thetruck-mounted carriage, and a travelling crane positioned at the loadingstation and adapted to transfer the ore receptacle between the chassisand carriage for movement thereon to the unloading station where the oreis dumped into the ore bin in which the ore receptacles are providedwith front and rear pairs of trunnions projecting from the sides thereofand adapted to support the same on the truck chassis, and the wheeledcarriage includes a supporting frame having front and rear trunnionsupporting means depending therefrom positioned to receive the trunnionson the ore, receptacles and adapted to maintain the latter insubstantially level relation while traversing the inclined trackwaywhere the front pair of trunnion supports on the carriage are adapted toreceive the rear pair of trunnions on the ore receptaclefor pivotalmovement therein and the rear pair of trunnion supports on the carriageare movable from an extended position in supporting relation to thefront pair of trunnions on the ore receptacle to a retracted positiondisengaged therefrom that permits the rear end of said receptacle to belowered thereby emptying its contents andmeans for retracting said reartrunnion supports and lowering the rear end of said receptacle.

2. An ore haulage system of the type used in open pit mines and the likewhich comprises, an inclined trackway laid on the sloping walls of thepit, a loading station on the inclined trackway near the working face ofthe mine, an unloading station including an ore bin located on thetrackway above the loading station, a wheeled carriage having front andrear pairs of trunnion supports mounted on the trackway for movementbetween the loading and unloading stations, hoist means operativelyconnected to the carriage for moving same up and down the trackway,truck-type vehicles movable between the working face and loadingstation, each vehicle having a wheeled chassis provided with front andrear pairs of trunnion supports, an open-topped ore receptacle havingfront and rear pairs of trunnions detachably mountable on the trunnionsupports of both the truck chassis and wheeled carriage, and meanscomprising a travelling crane located at the loading station and adaptedto transfer the ore receptacles between said chassis and carriagewherein the front pair of trunnion supports on the carriage is adaptedto receive the rear pair of trunnions on the ore receptacle for pivotalmovement therein and the rear pair of trunnion supports on the carriageare movable from an extended position in supporting relation to thefront pair of trunnions on the ore receptacle to a retracted positiondisengaged therefrom, means acting on the rear trunnion supports to movesame to a retracted position and means adapted to support and lower thefront pair of trunnions when the rear trunnion supports are retractedpermitting the rear end of said receptacle to be lowered thereby empting its contents.

3. An ore haulage system of the type used in open pit mines and the likewhich comprises, an inclined trackway laid on the sloping walls of thepit, a loading station on the inclined trackway near the working face ofthe mine, an unloading station including an ore bin located on thetrackway above the loading station, a wheeled carriage having front andrear pairs of trunnion supports mounted on the trackway for movementbetween the loading and unloading stations, hoist means operativelyconnected to the carriage for moving same up and down the trackway,truck-type vehicles movable between the working face and loadingstation, each vehicle having a wheeled chassis provided with front andrear pairs of trunnion supports, an open-topped ore receptacle havingfront and rear pairs of tnunnions detachably mountable on the trunnionsupports of both the truck chassis and wheeled carriage, and meanscomprising a travelling crane located at the loading station and adaptedto transfer the ore receptacles between said chassis and carriagewherein the front pair of trunnion supports on the carriage is adaptedto receive the rear pair of trunnions on the ore receptacle for pivotalmovement therein and the rear'pair of trunnion supports on the carriageare movable from an extended position in supporting relation to thefront pair of trunnions on the ore receptacle to a retracted positiondisengaged therefrom permitting the rear end of said receptacle to belowered thereby emptying its contents and wherein the unloading stationincludes an automatic dumping assembly operative to lower the rear endof the loaded ore receptacle and empty the contents thereof into the orebin, said dumping assembly including a dump ing scroll having anupwardly inclined section on the downhill end thereof positioned inalignment with the rear pair of trunnions and adapted to raise same thuselevating the rear end of said receptacle so that the rear pair oftrunnion supports on the carriage are unloaded, a cam follower dependingfrom each of said rear pair of trunnion supports operative uponactuation to move the latter between extended and retracted positions, acam track positioned in alignment with one of the cam followers andadapted to actuate same following unloading of said rear pair oftrunnion supports operatively associated therewith, and a downwardlycurving arcuate section on the uphill end of the dumping scrollpositioned and adapted to receive the rear pair of trunnions and lowerthe rear end of the ore receptacle following movement of said rear pairof trunnion supports from extended to retracted position.

4. An ore haulage system of the type used in open pit mines and the likewhich comprises, an inclined trackway laid on the sloping Walls of thepit, a loading station on the inclined trackway near the working face ofthe mine, an unloading station including an ore bin located on thetrackway above the loading station, a wheeled carriage having front andrear pairs of trunnion supports mounted on the trackway for movementbetween the loading and unloading stations, hoist means operativelyconnected to the carriage for moving same up and down the trackway,truck-type vehicles movable between the working face and loadingstation, each vehicle having a wheeled chassis provided with front andrear pairs of trunnion supports, an open-topped ore receptacle havingfront and rear pairs of trunnions detachably mountable on the trunnionsupports of both the truck chassis and wheeled carriage, and meanscomprising a travelling crane located at the loading station and adaptedto transfer the ore receptacles between said chassis and carriagewherein the carriage includes a frame carrying both pairs of trunnionsupports and mounted to receive and maintain the ore receptacle insubstantially level position while traversing the inclined trackway, theuphill end of the frame being hingedly connected to the correspondingend of the wheeled carriage and jack means interconnecting the downhillends thereof, said jack means being operative upon actuation to vary theangular relation between said carriage and frame.

5. The ore haulage system: as set forth in claim 1 in which, atransverse track-way intersects the inclined trackway at the loadingstation, and the traveling crane is of the Gantry-type mounted formovement along said transverse trackway.

6. The ore haulage system as set forth in claim 5 in which, thetransverse trackway extends on opposite sides of the loading station,and one Gantry-type traveling crane is mounted on the transversetrackway of each side of the unloading station.

7. The ore haulage system as set forth in claim 5 in which, two inclinedtrackways are provided in side-hyside substantially parallel relationeach of which has a separate loading station, unloading station, hoistmeans and wheeled carriage, the transverse trackway intersects bothloading stations and extends laterally therefrom, and a separatetraveling crane is mounted on the transverse trackway in position topick up and deliver ore receptacles to and from each of the loadingstations.

8. The ore haul-age system as set forth in claim 6 in which each of thecranes is provided with a sling having upwardly opening hooks locatedand adapted to receive both the front and rear pairs of trunnions forlifting and transporting the ore receptacle between the chassis andcarriage.

9. The ore haulage system as set forth in claim 2 in which the carriageincludes a frame carrying both pairs of trunnion supports and mounted toreceive and maintain the ore receptacle in substantially level positionwhile traversing the inclined trackway.

10. The ore haulage system as set forth in claim 3 in which, the rearpair of trunnion supports is hingedly mounted on the carriage forrockable movement about a substantially longitudinal axis, the camfollower includes a rocker arm having one end fixedly attached to saidrear trunnion support associated therewith and a roller on the otherend, and the cam track includes a channelshaped section positioned toreceive the roller and angularly disposed relative to the direction ofmovement of the carriage such that the rocker arm is tilted as saidroller traverses said channel-shaped section.

11. The ore haulage system as set forth in claim 3 in which stop meansinterconnect the rear trunnion supports with the carriage, said stopmeans being operative to maintain said rear trunnion supports inextended position when loaded.

12. The ore haulage system as set forth in claim 3 in which the camtrack and dumping scroll are each operatively associated with thetrackway for movement between an operative position wherein the orereceptacle will be emptied during its passage toward the unloadingstation and an inoperative position that allows said ore receptacle tobypass said unloading station without being dumped.

13. The ore haulage system as set forth in claim 3 in which, the rearpair of trunnion supports is hingedly mounted on the carriage forrockable movement about a substantially longitudinal axis, the camfollower comprises an arm mounted for reciprocal movement with one endthereof pivotally attached to said rear trunnion support operativelyassociated therewith and the other end provided with a roller journalledfor rotation about an axis substantially normal to the axis ofreciprocal movement, and the cam track included a channel-shaped sectionpositioned to receive the roller and angularly disposed relative to thedirection of movement of the carriage such that said arm is moved in thedirection of its length as said roller traverses said channel-shapedsection.

14. The ore haulage system as set forth in claim 4 in which the jackmeans comprises a scissor-type linkage having a pair of pivotallyinterconnected links with the opposite ends thereof pivotally attachedto the frame and carriage, and -a screw operatively connected to thecommon pivotal connection between the links and to a retaining elementfixed in relation to the latter whereby rotation of said screw withinsaid retaining means operates to vary the angular relation between saidlinks.

15. The ore haulage system as set forth in claim 11 in which, the rockerarm projects inwardly from the rear trunnion support associatedtherewith, and the channelshaped section of the cam track is upwardlyinclined at a steeper angle than the angle of inclination of thetrackway.

16. The ore haulage system as set forth in claim 11 in which, the rockerarm projects outwardly from the rear trunnion support associatedtherewith, and the channelshaped section of the cam track is downwardlyinclined in a direction opposite to the angle of inclination of thetrackway.

17. The ore haulage system as set forth in claim 13 in which the camtrack lies in a plane substantially parallel to the slope of the pitwallalong the trackway.

References Cited in the file of this patent UNITED STATES PATENTS1,647,648 Moore et al. Nov. 1, 1927 1,731,909 Rogers Oct. 15, 19291,966,390 Hick July 10, 1934 1,993,081 Anderson Mar. 5, 1935 FOREIGNPATENTS 407,129 Germany July 29, 1925 1,876 Australia Sept. 21, 1926981,645 France Jan. 17, 1951

